Anal Dilatations After PSARP: Current Practice, Evidence & Future Directions in Pediatric Colorectal Surgery

Alberto Pena espouses routine dilation starting at 2 weeks for every child with an anorectal malformation repair, regardless of age, and considered it so integral to success that he would not offer revision surgery to older children unwilling to dilate.

The Cincinnati protocol targets 12mm Hegar diameter for newborns in the first 4 months, 13mm for the second 4 months, 14mm up to one year, with increases thereafter based on Pena's published table.

The Cincinnati dilation technique involves inserting the dilator for 30 seconds, removing it, reinserting for 30 seconds (one complete dilation), performed twice daily, advancing 1mm in size every 7 days until goal size is reached.

Once goal size is reached, dilations are tapered in frequency over approximately 9 months: once daily for 1 month, every other day for 1 month, with the last 3 months being once monthly.

Dr. Rosen's current practice cutoff for routine dilations is 1.5 to 2 years of age, as older children remember the procedure and fighting with the child escalates emotional trauma for both child and parent.

When two patients allocated to the dilation arm who did not perform consistent dilations are moved to the non-dilation arm, the stricture rate becomes approximately 37% without dilation vs 14% with dilation.

Heineke-Mikulicz strictureplasty is a very good operation for surface strictures at the anal canal, but once a stricture sets in, you never truly get a soft, stretchable, compliant anal canal.

Studies supporting strictureplasty have not followed patients for 10, 20, or 30 years to assess long-term functional impact and ability to avoid permanent ostomy.

Long-term functional outcomes in anorectal malformation patients must account for multiple factors: voluntary bowel movements, soiling rates, dependence on enema regimens, rates of returning to ostomy, and need for antegrade enema surgery.

Long strictures represent failure of pull-through blood supply rather than failure of dilation, and opening just the surface will not adequately treat a long strictured segment.

Starting dilations under anesthesia may send the wrong message to parents that the procedure is traumatic enough to require anesthesia, whereas performing it awake in clinic demonstrates to parents that the child can tolerate it.

Some children tolerate dilations without crying or resistance, while others clearly find the process unpleasant, but many therapies deemed important are challenging to get through.

Going too fast with dilations—advancing to larger sizes before the tissue is ready—can cause macro-tearing and create painful anal fissures that bleed, adding pain and bleeding to what should be a gentle process.

If there is any pink on the lubricating jelly when removing a dilator, the starting size should be reduced by one millimeter to ensure a gentler introduction for the family.

Recent articles from Nationwide describe successful use of Kenalog injection to treat early strictures, which Dr. Rosen now uses at 6-week evaluation in older children instead of prolonged dilation protocols.

For children over 18 months where routine dilation is not planned, Dr. Rosen creates a slightly larger neo-anus at surgery (extending beyond the traditional center point of the muscle complex) to allow for some settling.

Properly designed trials must stratify by malformation type (perineal, bulbar, prostatic, vestibular fistulas) and control for confounding factors like tethered spinal cord or associated spinal malformations.

Pure perineal fistulas have the best outcomes and typically do not have continence issues in the absence of surgical complications, making them less ideal for studying the impact of dilations on function.

Vestibular fistulas are currently too heterogeneous for study because some surgeons still use traditional PSARP while others have adopted Belinda Dickey's perineal body-sparing approach.